Better Preservation with Wireless Monitoring

Carnegie Museum of Natural History (CMNH), in Pittsburgh, preserves 22 million specimens and artifacts from natural history disciplines such as anthropology, paleontology, botany, ornithology, mammalogy, and geology.

Museum pieces include photographs, taxidermy specimens, and bronze and wood items. Additionally, CMNH houses Diplodocus carnegii, the nearly complete fossilized skeleton of a massive plant-eating dinosaur, which is used by paleontologists to identify other fossils of its kind.

These irreplaceable items must be maintained under strict and stable environmental conditions in order to prevent their deterioration. To verify the existing environmental conditions of their collections, CMNH hired interior environmental specialists Landmark Facilities Group (LFG) to perform an interior environmental survey. Due to the complexity of the buildings involved and the benefits of Onset’s HOBO® line, LFG recommended using Onset’s ZW series wireless HOBOs for the collection of temperature and relative humidity data throughout CMNH’s 420,000 square feet of interior space, spread over three buildings.

Challenge
It is especially difficult to monitor and maintain stable temperature and humidity levels in CMNH’s largest building because it’s comprised of three separate additions. Furthermore, the HVAC systems throughout the buildings are made up of several different makes and models, installed at different times – some with dehumidifiers and some without.

What’s more, the main museum building, which was built in 1907, lacks both a vapor barrier and insulation. The building’s primary construction is stone, steel, and concrete, and due to its standing as an historical landmark, there are restrictions on making alterations to it. This includes using screws to secure conservation equipment to walls in some areas.

The museum has a glass roof, which adds to the difficulty of temperature and humidity control. Maintaining the museum standard of 40% to 50% relative humidity in all storage areas, preparation rooms, and exhibition halls is a tall order for Gretchen Anderson, CMNH’s conservator. Anderson must also maintain a tight three-degree temperature range.

Solution
To overcome these challenges, LFG deployed 50 HOBO ZW series wireless data nodes with integrated temperature and relative humidity sensors. The HOBO data nodes were chosen for their real-time data capability, compact size (suitable for discreet deployment), instant notification potential, and onboard buffer memory to ensure that no data are lost.

Despite stone, brick, and cement walls, and an abundance of metal museum-quality collections cabinets, the wireless system functions reliably. Data loggers monitor CMNH’s entire complex of buildings, from basements to attics. The nodes are attached to walls and in some cases on top of cabinets. To mount the data nodes in historic museum spaces, non-marking 3M adhesive strips were used. One wireless node is deployed outside in order to analyze how outdoor ambient air temperature and moisture content affects the museum’s interior environment.

Results
With the installation of the new wireless monitoring solution, employees at CMNH can now immediately identify, diagnose, and resolve HVAC equipment dysfunction. In just a few shorts months, the sensors have already helped them to detect a malfunctioning humidification system and identify a crack in a wall, both of which had been contributing to high humidity levels. Prior to installing the new system, workers could spend up to three weeks identifying similar problems, but now they can often pinpoint failures and get environmental conditions back on track in a few hours.

Before implementing the wireless system, CMNH used a combination of stand-alone data loggers, drum hygrothermographs, and hand-held digital monitors. “I had twenty stand-alone data loggers deployed and it took me two or three days to offload the data and prepare environmental reports for collections managers,” says Anderson. “Now I have fifty wireless nodes deployed and it takes me one day to generate the same reports.”

Staff members at CMNH especially like the HOBOware® software’s ability to plot data from different data loggers on one single graph. With this simple-to-use capability, they can easily compare sets of data. The museum conservator is also able to export raw data to an Excel® workbook template to prepare reports for collections managers and lenders.

Conclusion
Looking ahead, CMNH plans to use HOBO data loggers for light and energy monitoring to help reach the museum’s energy efficiency goals. “Our recent environmental monitoring endeavor is a test project that I hope will become a model for other museums to duplicate so that they better preserve their collections,” says Anderson.

CMNH’s wireless data logging project, which is funded by the Institute for Museum and Library Services – Conservation Project Support, is a collaboration between the museum and Landmark Facilities Group.

To discuss your monitoring project with an Onset Applications Specialist, please call 800-564-4377.